During the last 40 years many lipopeptide antibiotics have been isolated and characterized. These lipopeptides can be grouped into several categories: 10-membered rings; 8-membered rings; 16-membered rings, etc. The most notable lipopeptide from the 10-membered ring group is daptomycin that is currently progressing through clinical trials. However, this is the only member of this diverse group, which has progressed this far. The primary goal of this project is to elucidate Structure Activity Relationships (SAR) around a 10-membered lipopeptide ring. Once we have a more detailed understanding of this SAR, the goal of Phase II would be to make modifications to the basic molecule that will be screened for increased activity against Enterococcus to look for compounds which could be developed as preclinical candidates.